Sanakirja.org

Määritelmät

Substantiivi

1. An act of retracting or withdrawing (a mistake, a statement, etc.); a retraction.
2. A pulling back, especially (military) of an army or military troops; a pull-back, a retreat; also, a signal for this to be done.
3. (group theory) A subgroup of a given group such that there is a surjective endomorphism from the ambient group to the subgroup which is constant on the subgroup; in this case the subgroup is a retract of the ambient group. In symbols: ${\displaystyle H}$ in ${\displaystyle G}$ is a retract of ${\displaystyle G}$ if there exists a surjective homomorphism ${\displaystyle \sigma }$ from ${\displaystyle G}$ to ${\displaystyle H}$ with σ|_H = \operatorname{id}.
4. (topology) The target of a retraction.
5. Synonym of retreat (“an act of accidentally injuring a horse's foot by incorrectly nailing it during shoeing”).

Verbi

1. To cancel or take back (something, such as an edict or a favour or grant previously bestowed); to rescind, to revoke.
2. To pull (something) back or back inside.
3. (specifically, zoology) To draw (an extended body part) back into the body.
4. To break or fail to keep (a promise, etc.); to renege.
5. To take back or withdraw (something that has been said or written); to disavow, to repudiate.
6. (rare) To avert (one's eyes or a gaze).
7. (phonetics) To pronounce (a sound, especially a vowel) farther to the back of the vocal tract.
8. (games) Originally in chess and now in other games as well: to take back or undo (a move); specifically (card games) to take back or withdraw (a card which has been played).
9. (obsolete) To hold back (something); to restrain.
10. (intransitive) To draw back; to draw up; to withdraw.
11. To decline or fail to do something promised; to break one's word.
12. Of something said or written (such as published academic work): to take back or withdraw.
13. (card games, archaic) To change one's mind after declaring an intention to make a certain move.